👤 Csilla Sipeky

Both the natural variants of the apolipoprotein A5 (APOA5) and the glucokinase regulatory protein gene (GCKR) have been shown to associate with increased fasting triglyceride levels. Here, we investigated the possible association of the functional variants of these two genes with non-fasting triglyceride levels and their susceptibility nature in ischemic stroke. A total of 513 stroke patients and 172 healthy controls were genotyped. All the APOA5 variants (T-1131C, IVS3 + G476A, C56G, and T1259C) were associated with increased triglyceride levels in all stroke patients and controls; except for T1259C, they all conferred risk for the disease. No such association was found for the examined GCKR rs1260326 (C1337T) variant. Furthermore, we examined the effects of specific combinations of the GCKR rs1260326 and APOA5 polymorphisms. Our findings confirmed the previous results regarding the association of APOA5 variants with triglyceride-level increase and stroke susceptibility of these alleles. By contrast, we could not detect any association of the studied GCKR allele with triglyceride levels or with the susceptibility of stroke in the same cohort of patients. In addition, the effect of APOA5 did not change significantly when specific combinations of the two genes were present. Show less

Recent genome-wide studies identified several genetic variants associated with blood lipid level alterations. Because affected lipid metabolism can confer risk to the development of ischaemic stroke, we studied three polymorphisms reportedly associated with triglyceride-level changes, rs17145738 and rs3812316 of the MLXIPL locus, and rs4846914 variant of GALNT2 gene in biobanked samples of patients with stroke. This pool of samples was previously investigated for haplotype tagging minor alleles of apolipoprotein A5 gene (T-1131C, T1259C, IVS3+G476A and C56G), and an association was found between the minor allele carriage and the triglyceride levels, and also these variants were found to confer risk to the development of stroke. Here, a total of 467 patients with stroke, stratified as large vessel, small vessel and mixed stroke groups, and 156 control subjects were genotyped using PCR-RFLP methods. In the current study, we could not verify association of the variants analyzed either with triglyceride and total cholesterol levels or with the risk of ischaemic stroke susceptibility. The data presented here revealed differentiated risk nature of the triglyceride level modifying natural gene variants. Show less

T-1131C, T1259C and IVS3+G476A are naturally occurring variants of the apolipoprotein A5 (APOA5) gene and their possible impact on the development of ischemic stroke was investigated in the present study. PCR-RFLP assays were used to determine the distributions of the APOA5 alleles in small-vessel, large-vessel and mixed subgroups of 378 patients and in 131 stroke-free control subjects. Increased triglyceride levels were found in subjects carrying -1131C, 1259C, IVS3+476A alleles in all stroke groups and in the controls. The -1131C and IVS3+476A alleles, but not the T1259C variant, showed significant accumulation in all stroke subgroups. Logistic regression analysis adjusted for age, gender, body mass index, total cholesterol level, ischemic heart disease, hypertension, diabetes mellitus, smoking-and drinking habits revealed that the IVS3+476A allele represents independent susceptibility factor for stroke (odds ratio for small-vessel: 4.748; large-vessel: 3.905; mixed: 2.926; overall: 3.644 at 95% confidence interval; p<0.05), we could also confirm the previously verified pathogenic role of the -1131C variant. All of the 3 APOA5 variants are associated with elevated triglycerides, but only the -1131C and the IVS3+476A alleles confer risk for all types of ischemic stroke; such an association could not be detected for the 1259C allele. Show less

The -1131C is a naturally occurring variant of the apolipoprotein A5 (ApoA5) gene, which has been shown to associate with increased triglyceride levels. This variant has also been shown to confer risk for development of ischemic heart disease and stroke. The gene is in linkage disequilibrium with factors known to correlate with impaired glucose homeostasis. These observations prompted us to study the prevalence of the ApoA5 -1131C allele in patients with metabolic syndrome. A total of 201 metabolic syndrome patients and 210 controls were studied. In both groups the triglyceride levels of patients with -1131C allele were significantly increased compared to the subjects with -1131T allele (3.22+/-0.43 mmol/l vs. 2.24+/-0.12 mmol/l, p<0.01 in the metabolic syndrome patients; 2.10+/-0.19 mmol/l vs. 1.22+/-0.05 mmol/l, p<0.01 in the controls). In metabolic syndrome patients the prevalence of the ApoA5 -1131C variant was increased compared to the healthy controls (11% vs. 6.20%). Multiplex regression analysis model adjusted for age, gender, serum total cholesterol levels, acute myocardial infarction and stroke events revealed that the examined ApoA5 variant confers risk for the development of metabolic syndrome: the odds ratio at 95% confidence interval was 3.622 (1.200-10.936), p=0.02. Our findings strongly suggest that this variant is a risk factor for the development of hypertriglyceridemia and metabolic syndrome. Show less